Changes in Muscle Mass, Strength, and Muscle Protein Synthesis in Response to 5 Days of Bedrest in Young, Healthy Adults

What this Trial Is About

Researchers are studying how five days of strict bedrest affect muscle mass, strength, and metabolic function in healthy young adults aged 18 to 30. The study aims to understand how skeletal muscle volume, strength, fatigue resistance, whole-body insulin sensitivity, mitochondrial function, and muscle protein synthesis change during this short-term disuse. This research addresses gaps in current knowledge about muscle loss and metabolic changes during clinically relevant bedrest periods. Participants will follow a 19-day study schedule, starting with baseline testing, then five days of their usual activities, followed by five days of strict bedrest where participants remain mostly horizontal but can sit up in bed and use a wheelchair for bathing and bathroom needs. Their diet and physical activity are controlled and monitored throughout. Tests include magnetic resonance imaging of thigh muscles, strength and power assessments, mixed meal tolerance tests, muscle biopsies, and blood sampling. During the study, participants will undergo repeated measurements of muscle volume, strength, fatigue, protein synthesis rates, insulin sensitivity, glucose metabolism, mitochondrial function, and muscle structure. These assessments happen before, during, and after the bedrest and control periods. The study also includes functional tests like the supine to stand test. The total involvement spans about 19 days, with careful monitoring of diet, activity, and health markers to track changes caused by bedrest.

Human Skeletal Muscle Response to 5 Days of Bedrest in Young Adults